Solid-State Battery Anode Layer Structure for Lithium Interface Stability

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Solution Overview

Problem

All-solid-state secondary batteries face issues with short circuits and degraded cycle characteristics due to lithium deposition at the solid electrolyte-anode interface and increased interfacial resistance, which affects their safety and performance.

Innovation Solution

The battery design includes a cathode, an anode with a first anode active material layer containing an M1-M2Ox composite or Li-M1-M2Ox composite, and a second anode active material layer with a carbon-containing material, arranged between the anode current collector and the first anode active material layer, to enhance lithium diffusion and interfacial stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a solid electrolyte layer and anode are simply stacked, then the battery structure is simple, but the effective interface area between the solid electrolyte layer and anode becomes smaller, increasing interfacial resistance and internal resistance

Engineering Contradiction:

Improvebattery structureVSAvoidinterfacial resistance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces a porous intermediate layer between the solid electrolyte and anode. This porous structure dramatically increases the effective interface area for lithium ion transfer, reducing interfacial resistance and internal resistance while maintaining a relatively simple overall battery structure.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent uses a composite intermediate layer combining porous structure with specific materials (such as Al, Cu, or their oxides) that have both high lithium ion conductivity and good mechanical properties. This composite approach simultaneously addresses electrical conductivity, mechanical stability, and surface area requirements.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If a solid electrolyte is used, then fire or explosion risk is greatly reduced, but lithium may locally deposit at the solid electrolyte-anode interface, grow and penetrate the solid electrolyte layer, resulting in short circuit

Engineering Contradiction:

Improvefire or explosion riskVSAvoidshort circuit risk

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces an intermediate layer as a mediator between the solid electrolyte and anode. This intermediate layer prevents direct contact and potential short circuits while facilitating lithium ion transfer, thus eliminating fire/explosion risks of liquid electrolytes and preventing dendrite-induced short circuits.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The porous intermediate layer acts as a cushioning layer that prevents lithium dendrites from penetrating through the solid electrolyte. The porous structure and mechanical properties of the intermediate layer absorb and distribute stress, preventing dendrite growth and potential short circuits before they can occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration prevents short circuits, improves lithium ion diffusivity, and enhances the cycle characteristics and lifespan of the battery by controlling void formation and increasing the surface area for lithium diffusion.

Implementation Method 1

improves lithium ion diffusivity

Methodology Applied

Scientific EffectLithium ion diffusion: Diffusion

Implementation Method 2

forming a plurality of pores in the first anode active material layer to prepare a porous first anode active material layer

Methodology Applied

Scientific EffectPorosity: Porosity

Implementation Method 3

M1 is a first metal and M2 is a second metal, the first metal and the second metal are each independently at least one element that reacts with lithium to form a lithium alloy or a lithium compound

Methodology Applied

Scientific EffectLithium alloy formation:

Data Source

PatentUS20240006595A1All-solid-state secondary battery and method of preparing the same

Publication Date: 2024.01.04 SAMSUNG ELECTRONICS CO LTD

AI summary

An all-solid-state battery including a cathode including a cathode active material; an anode including an anode current collector, a first anode active material layer, and a second anode active material layer; and a solid electrolyte arranged between the cathode and the anode, wherein the first anode active material layer is arranged adjacent to the solid electrolyte and comprises M1-M2Ox, Li-M1-M2Ox, or a combination thereof, wherein the first metal and the second metal are each independently at least one element that reacts with lithium to form a lithium alloy or compound, x>0, the second anode active material layer is arranged between the anode current collector and the first anode active material layer and includes a second anode active material, and the second anode active material includes a carbon-containing anode active material, or a carbon-containing anode active material, and at least one of a metallic or metalloid anode active material.